.divCols{
  display:flex;
  justify-content: space-around;
}
.banner {
  width: 100%;
  height: 100%;
  overflow-x: scroll; /*添加横向滚动条*/
  white-space: nowrap;/*不换行*/
}

.left {
  width: 10%;
  margin-right: 2%;
  display: inline-block;/*设为inline-block*/
}
.right {
  width: 90%;
  margin-right: 2%;
  display: inline-block;/*设为inline-block*/
}